System for the management of multiple time-critical data streams

Abstract

A networked computer system for storing and presenting multimedia data distributes that data among multiple storage devices of the system. The system includes a plurality of computers, each of which supports at least one viewing station. Each viewing station has access to any file on any of the storage devices and can retrieve and display any file on demand. To provide an efficient system and, at the same time, reduce the probability that the viewing of multimedia data may be interrupted, the system allocates resources, prioritizes access to files, and buffers data prior to the data's delivery to video adapters.

What is claimed is: 
     
       1. A computer network system for storing and displaying video multimedia data clips, said system comprising: a plurality of computers, each computer having at least one storage device coupled thereto for storing a portion of said multimedia data clips;   display means for displaying said video multimedia data clips;   a computer network;   interconnecting resources for connecting each of said plurality of computers to said computer network, said interconnecting resources comprising data buffers for storing the digital information in said video multimedia data clips;   client means in each of the plurality of computers for retrieving video multimedia data clips from the local storage device coupled thereto and for sending requests for said video multimedia data clips over the computer network to other of said plurality of computer;   server means in each of the plurality of computers responsive to requests from other of said plurality of computers for providing one of the video multimedia data clips over the computer network to another of said computers making said requests;   local management means in each of said plurality of computers for allocating said interconnecting resources and for refusing one of said requests to prevent said data buffers from becoming overloaded during display of one of said video multimedia data clips; to prevent said interconnecting resources from becoming overloaded during display of one of said video multimedia data clips each of the plurality of computers capable of retrieving and providing video multimedia data clips over the computer network and for retrieving video multimedia data clips from the local storage device coupled thereto.   
     
     
       2. The computer network system of claim 1 wherein said display means comprises at least one viewing station, coupled to each computer, for displaying said retrieved video multimedia data clips. 
     
     
       3. The computer network system of claim 2 wherein said interconnecting means comprise: a processor;   a network adapter controlled by said processor; and   means controlled by said processor for transferring said video multimedia data clips between said computer network and said data buffers.   
     
     
       4. The network system of claim 3 wherein said local management means comprises means for monitoring usage of said interconnecting means and means for causing said server means to refuse said request when an amount of said digital information stored in said data buffers reaches a predetermined threshold. 
     
     
       5. A multimedia storage and presentation system for storing video clips, each clip comprising a plurality of segments, and for displaying said video clips in response to requests by viewers, said system comprising: a computer area network;   a plurality of computers connected to said computer network, each computer having attached thereto at least one storage device at least one viewing station, input means for allowing said viewers to request display of a specific video clip on said at least one viewing station and buffer means for temporarily storing segments of said specific video clip prior to display;   client means in each of the plurality of computers for retrieving one of the video clips from the local storage device coupled thereto and for sending a request for one of said video clips over the computer network to other of said plurality of computers;   server means in each of said plurality of computers responsive to said request for retrieving said specific video clip from selected storage device coupled to said computer, said server means having a predetermined maximum retrieval capacity;   means cooperating with said server means in one of said plurality of computers for monitoring said buffer means in said one of said plurality of computers coupled to said network to determine a number of video clip segments retrieved from said selected storage device; and stored in said buffer means; and   means responsive to said number of video clip segments stored in said buffer means and to said maximum retrieval capacity for controlling said client means and said server means to refuse said viewer request to display said specific video clip when said maximum retrieval capacity would be exceeded or said number of said video clip segments stored in said buffer means exceeds a predetermined threshold.   
     
     
       6. In multimedia storage and presentation system for storing video clips, each video clip comprising a plurality of segments, and for displaying said video clips in response to requests by viewers interacting with a computer system the system including a network, a plurality of computers connected to said network, each computer having attached thereto at least one local storage device for storing some of said video clips for distribution thereto and to other of the computers connected to said network, at least one viewing station, input means for allowing said viewers to request display of a specific video clip on said at least one viewing station and buffer means for temporarily storing segments of said specific video clip prior to display, a method of accessing video clips comprising the steps of: A. in response to a view of request a viewer request for a specific video clip receiving by one of the computers coupled to the network, locating said specific video clip in the at least one local storage device attached to said one computer;   B. if said specific video clip is not found in said at least one local storage device attached to said one computer, locating another of said plurality of computers having attached thereto a selected storage device containing said specific video clip;   C. retrieving said specific video clip from said selected storage device in said another of said plurality of computers coupled to said network over a path having a predetermined maximum retrieval capacity;   D. monitoring said buffer means in said another of said plurality of computers coupled to said network to determine a number of video clip segments retrieved from said selected storage device and stored in said buffer means; and   E. refusing said viewer request to display said specific video clip when said maximum retrieval capacity would be exceeded during step C or said number of said video clip segments stored in said buffer means exceeds a predetermined threshold.   
     
     
       7. The method of claim 6 wherein step E comprises the steps of: E1. identifying data transfer resources involved in the data retrieval of step C;   E2. determining a maximum capacity of each data transfer resource identified in step E1;   E3. determining an average data capacity of each resource identified in step E1 involved in the data retrieval of step B; and   E4. reducing the maximum capacity determined in step E2 by the average data capacity determined in step E3.   
     
     
       8. The method of claim 7 wherein step E2 comprises the step of: E2A. maintaining a configuration table having contents relating to performance characteristics of each resource needed to display said specific video clip.   
     
     
       9. The method of claim 8 wherein the step E2 further comprises the steps of: E2B. recording total resource utilization; and   E2C. comparing the total resource utilization with performance characteristics stored in said configuration table.   
     
     
       10. The method of claim 9 wherein step E2C comprises the steps of: E2C1. identifying a data transfer resource having the least available capacity at the time of a viewer request; and   E2C2. comparing the utilization of the resource identified in step E2C1 with performance characteristics stored in said configuration table.